Survival of the Fleetest: Four hairy-mammoth hot rods defy reason and the laws of physics with equal glee.

Let’s be clear: In the matter of mammoths, we understand the distinction between woolly and hairy. Woolly mammoths were the elephantine creatures that disappeared about 8000 to 10,000 years ago. Guys hunted ’em with pointed sticks, which was reportedly a hairy experience.

But hairy also applies to this collection: the BMW X5 M, the Jeep Grand Cherokee SRT8, the Land Rover Range Rover Sport Supercharged, and the Porsche Cayenne Turbo S. Mammoths all—not a one under 4700 pounds or propelled by less than 420 horsepower. And all of them astoundingly quick on their feet, particularly for creatures in this weight class. Astoundingly quick, period, come to think of it. The slowest of the lot—if slow is the right word—rumbles to 60 mph in 5.1 seconds.

What does it all mean? In an age of escalating alphabetic concerns—MPG, CO2, NOX—this foursome may seem seriously out of step and as ripe for extinction as the old woollies. There would be big gas-guzzler fees attached to their already weighty price tags were it not for their exempt status—they’re trucks. The best EPA ratings belong to the Porsche—12 mpg city and 19 highway, numbers that are hard to associate with the word “best.” Three of the four averaged 14 mpg during our 450-mile tour of western Michigan, and the fourth, just 13.

You could excuse this rabid thirst if there was real work involved—heavy towing, for example. But that’s not the case, and, in fact, at least one of these muscle-bound mastodons is rated for just 3500 pounds. You can tow that much with a minivan. While some of the others can drag a lot more than that—the Porsche and the Range Rover are both rated for 7716 pounds—we’ll bet you won’t see many of these super-utes held back by trailers. They are not rational. They exist for going improbably fast, for astonishing the Corvette driver in the other lane when the light turns green. Jaysez! What the hell was that?

We should note that the super-ute precedent was established long ago. Remember the Lamborghini LM002? Conceived as an off-road-capable military scout vehicle, it sported a 5.2-liter Lamborghini V-12 fed by six Weber carburetors (remember carburetors?) to the tune of 444 horsepower and 368 pound-feet of torque. The people who develop vehicles for military applications don’t seem to worry too much about mass, and that was true with this one: 6780 pounds, which makes our contemporary quartet look almost dainty.

But even burdened with well over three tons, the V-12 was able to push that big Lambo to 60 mph in 7.7 seconds, which was pretty quick in 1987. More important, it looked like nothing else on U.S. roads, making its $120,000 price tag and 8-mpg thirst acceptable to seekers of exclusivity. But, of course, a gallon of gas was about a buck back then, and it was a much different world.

Our contemporary mammoths don’t have the LM002’s unique visual distinction. Basically, these are all familiar faces, high-output variations of less-explosive models; their distinctions are subdermal. But those are big distinctions. We’re also looking at some big price disparities. That factor, plus the sharply differing personalities of the four vehicles, made scoring a challenge. But as always, we emerged with distinctions of our own.

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If our test had included an off-road component, there’s no doubt the Range Rover would have fared better in the scoring. As you’d expect of a vehicle from a company that’s made a religion of roadless competence, its four-wheel-drive system is the quintessence of technical sophistication, pretty much as good as it gets, though the Cayenne also gets good marks in this regard.

However, the BMW X5 has no off-road pretensions whatsoever, so given that, and the absence from this test crew of our man John Phillips—who dearly loves taking soft-road SUVs into bogs and fens until winching is required—we kept our evaluation primarily on pavement.

Still, even omitting a key part of its game, the Range Rover gave a good account of itself, surprising the test crew with its all-around performance.

The surprise was rooted in two key specifications: curb weight and height. Essentially a slightly abbreviated version of the Land Rover LR3/LR4, the Sport is the shortest vehicle in this roundup, and at 5840 pounds, by far the heaviest—511 pounds more than the next-heftiest X5, 1072 more than the Jeep. Height plus ground clearance designed to accommodate off-road use (6.8 inches minimum, and upwardly adjustable) plus a lofty seating position equals a high center of gravity. Multiply that by mass and all-season tires, and you seemingly have a prescription for sluggish responses and relatively low cornering speeds.

But that’s one of the dynamic areas where the Range Rover acquits itself well. A fair percentage of its extra mass can be traced to a structure that’s as stiff as a cantilever bridge, though both the BMW and the Porsche achieve comparable chassis rigidity at much lower weight. Still, a solid structure, plus the performance of the Range Rover’s four-corner control-arm auto-adjusting air-spring suspension, keeps this tall boy remarkably level when the turns are coming fast and furious. Its agility isn’t reflected in a so-so 0.79-g skidpad performance and fourth-place showing in the lane-change test; both were inhibited by the nondefeatable stability control. But the Range Rover chassis engineers anticipated the “inevitable aggressive-driving stints,” and take our word for it—this big boy can dance.

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Similarly, though it was fourth in the formal sprints, the Range Rover wasn’t exactly left gasping in the dust. At 510 horsepower and 461 pound-feet of torque—gains of 120 and 51, respectively—its new supercharged and intercooled 5.0-liter, aluminum V-8, the same engine used in the Jaguar XFR sedan, is saddled with the most bulk but still achieved 60 mph in 5.1 seconds, a 1.6-second improvement over the previous model.

The Range Rover drew its best marks in the “Vehicle” section of our score card, which scrutinizes elements such as ergonomics, comfort, styling, interior design, and fit and finish. There were a few dings—for relatively confined front-seat space, short front-seat cushions, and a center console that intrudes on the driver’s elbow. But a classic exterior design and a gorgeous interior give the Range Rover the most elegance, all the more impressive considering its relatively tame $74,195 base price.

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Though it’s not the quickest in this demented foursome, its blend of speed, grace, and mountain-goat “go anywhere” ability is unique.

When was the last time a $50,000 Jeep ($49,560 as tested, to be precise) looked like a bargain? This powerhouse from Chrysler’s SRT performance shop is the most expensive of Jeeps, but in this crowd its price tag—$32,785 less than the next vehicle in money rankings—seems almost reasonable. And if startling others with a burst of manic acceleration is your idea of SUV fun, this Jeep gets it done, and pronto. It’s not as fleet as the German mammoths, but 4.4 seconds to 60 mph and 13.2 at 104 mph in the quarter-mile is speedy indeed for a sport-ute, and that big Hemi V-8 makes such wonderfully menacing sounds in the process.

That is this Jeep’s fundamental (and intensely visceral) appeal—Chrysler’s 6.1-liter pushrod Hemi, the only naturally aspirated engine of the group. And it makes up for a number of other SRT8 traits that are not so appealing.

For example, with one important exception, the inner Jeep came in for a fair amount of logbook flak from drivers. Despite a lengthy list of upgrade options, the words “cheap-looking” occurred often. Exacerbated by a dark-gray color scheme inside, the Jeep’s plastics have a low-rent look in contrast to the high-zoot materials in the Range Rover and the Porsche. An invidious contrast, of course, given the vast disparities in price. But then, who says perceptions are always fair?

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Space is another interior debit, as in not enough of it, particularly for rear-seat passengers. On the other hand, a tilting and telescoping steering column, plus power-adjustable foot pedals, mitigates the space issue up front, and a set of excellent bucket seats—the exceptional interior element; we preferred them to the BMW’s—makes the Jeep a pleasant place to be, at least on smooth roads. One other small but nifty detail drew favorable attention: a digital oil-temp readout in degrees, as well as a ribbon-style gauge. Neat.

You noticed the smooth-road caveat regarding comfort? This also applies to handling. On the well-maintained surfaces of the test track, the Jeep held its own in the skidpad and lane-change tests despite limits imposed by all-season tires and a stability-control system that can’t be completely shut down. But on pavement afflicted with warts, divots, and frost heaves, it’s a different story. Stiff spring rates and the only live-axle rear suspension in the foursome combine to make the Jeep unpleasantly active, and directional stability becomes iffy in fast turns sprinkled with bumps. One logbook note referred to the Jeep’s ride as “Mr. Bobblehead.”

A steering system that tends toward numb doesn’t help, either. Nor does excessive road noise, transmitted via the suspension. Still, the call of the Hemi is hard to resist. Factor in price, and the Jeep edged out the Range Rover for third place by one point.

Beautifully appointed inside, highly competent in all its dynamics, and insanely fast, the Porsche suffered in our subjective scoring for its oil-sheik price. Base price to base price, the new-for-’09 Turbo S version of this tradition-defying Porsche is over $26,000 more than the Turbo model.

What do you get for the extra dough? Both are powered by a direct-injection, 4.8-liter twin-turbo aluminum V-8, but the S gets an extra dollop of maximum boost to its induction, which of course raises the power output: 550 horsepower versus 500, 553 pound-feet of torque versus 516. And that, in turn, reduces acceleration times: 4.1 seconds to 60—the quickest we’ve recorded for any Cayenne—and 12.6 at 112 mph in the quarter-mile.

Both numbers are 0.1 second behind the BMW, but beyond the quarter-mile mark, the Porsche really begins to assert itself: 17.8 seconds to 130 mph—0.3 second quicker than the BMW—topping out at an amazing 177 mph. The BMW gives up at 158.

Enhanced by a set of optional carbon-ceramic brakes ($8840, please), the Porsche dissipates speed just as quickly: 158 feet from 70 mph, best in test. That also applies to the skidpad performance—0.91 g, on a set of Michelin Latitude Sport tires (295/35R-21)—as well as the lane change: quickest, at a heady 66 mph.

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These are sports-car numbers. Add to that a beautifully crafted interior—not quite as showy as the Range Rover’s but its equal in terms of materials, with the best seats in this bunch, thanks in part to their wide range of adjustability. The Porsche’s three-mode air-spring suspension provides an exceptional balance between comfortable ride and aggressive response, exemplary in its management of the Cayenne’s considerable mass.

So what’s the problem? How does this extraordinary (blasphemous to 911 faithful) Porsche fall 16 points short of its rival from Bavaria?

There are multiple answers. The Cayenne took multipoint hits for its modest cargo capacity and its styling—no one could see beauty in that gaping-maw grille. Of more concern to Porsche’s dynamicists: The steering, though quick, at 2.7 turns lock-to-lock, seemed a little vague to some; the responses of the manual shifting of the six-speed automatic were soft compared with the Bimmer’s, and the thumb-operated shift switches were universally disliked; throttle response in full sport mode was abrupt; and some found the overall experience a little thin on driver involvement compared with the BMW, which cost the Porsche fun-to-drive points.

However, the real zinger is that swollen bottom-line number on the Monroney. To some, 50 extra horses at $528 per pony makes sense. But not here.

“Wicked fast!”

That was one of the first notes in the X5’s logbook, an impression reinforced by entry after entry as the quartet drove on. It was all too easy to tramp on the throttle, get the X5 through a turn, then check the speedo to find oneself rocketing along at triple-digit speed and accelerating. But, officer . . .

This didn’t come as a total surprise. Total surprise occurred four months earlier when we put an X6 M through its paces [“Ironmein,” October 2009]. Although its contours are, uh, unique, the X6 M is basically an X5 M dressed up for the burbs—similar mass, same suspension (multilink with stout coil springs at the front, multilink rear with air springs, bridge-girder anti-roll bars fore and aft), same aluminum 4.4-liter V-8 force-fed by a pair of twin-scroll turbos with huge intercoolers.And the same six-speed manumatic transmission feeds the same 555 horsepower and 500 pound-feet of torque (from 1500 rpm) to the same full-time all-wheel-drive system and limited-slip and torque-vectoring rear diff.

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So, no surprise, but eye widening—or is it eyeball flattening?—nonetheless. Though the X6 is no wraith at 5254 pounds, the X5 is 75 pounds heavier, at 5329 pounds, and stands 3.1 inches taller. Yet it is even quicker, thanks to launch control that our preproduction X6 lacked: four seconds flat to 60 mph, 100 mph in 10 seconds, and the quarter-mile in 12.5 seconds at 112 mph. Smokin’!

Braking performance—162 feet from 70 mph—also edged the X6 M’s, though by just one foot, and the Porsche stopped four feet better. But brake feel and stopping power remained consistent, regardless of abuse, and wouldn’t it be swell if all mainstream family sedans were capable of matching this aspect of performance?

For a vehicle in this weight class, the test-track numbers are simply incredible. But the X5’s responses in the world of fast curves, decreasing radii, and quick transitions are even more so. Despite its mass and high center of gravity, the big-bopper Bimmer maintains level cornering attitudes, and its eager responses to steering inputs is more reminiscent of an M3 than something weighing some 1700 pounds more.

The manumatic shifting of the six-speed transmission makes the Porsche’s Tiptronic seem flabby, enhancing the improbable sports-car sense of response. Though the X5’s stability-control system inhibits its performance in the lane-change test—it can’t be switched off fully, and it’s hard to see why you’d want to—in the real world, it attacks twists and turns like a cheetah sorting an antelope herd. Make that a really big cheetah.

A few dissatisfactions cropped up in the logbook. Though the X5 inspires more high-speed-handling confidence than its opponents, it ran out of suspension travel more than once on rough stretches, an unsettling phenomenon. The steering, though quick and unerringly precise, is a little heavy for some tastes. And the seats, as noted earlier, are a pretty relaxed fit compared with those of other BMW M vehicles.

There were also comments about the basic vehicle concept, along the lines of, “What was the point again?” But that applies to all four super-utes. And within the context of these four hairy mammoths, the X5 was, again, the Ultimate Driving Machine.

“Simply a joy to drive,” wrote one tester. Amen.

Epilogue

If Samuel Morse had been on hand to see these four in action, his famous telegraphic query might have been a two-parter, to wit: “What hath God wrought? And why?”